Researchers of Stanford University School of Medicine in the US have shown that the wearable technology Apple Watch can identify atrial fibrillation.

Atrial fibrillation is a condition of irregular heart rate. Given its elusive and sporadic symptoms, often the condition goes undetected. However, it is considered to be a leading cause of stroke and hospitalisation in the US.

Over 400,000 participants were enrolled in an eight-month-long Apple Heart Study launched through sponsorship by Apple in November 2017.

This study was carried out to determine whether the software on the Apple Watch could use data from the smartwatch’s heart-rate pulse sensor to detect atrial fibrillation.

Stanford University School of Medicine associate professor of cardiovascular medicine Mintu Turakhia said: “The study’s findings will help patients and clinicians understand how devices like the Apple Watch can play a role in identifying atrial fibrillation, a deadly and often undiagnosed disease.

“Additionally, these important findings lay the foundation for further research into the use of emerging wearable technologies in clinical practice and demonstrate the unique potential of large-scale app-based studies.”

Researchers found that only 0.52% of participants received a notification upon an irregular pulse.

Participants notified for an irregular pulse received follow-up care through heart-monitoring technique electrocardiography (ECG) patch.

Out of notified participants subsequently monitored by the ECG patch around two weeks later, 34% were identified with atrial fibrillation.

As atrial fibrillation is an intermittent condition, it went undetected in subsequent ECG patch monitoring.

On comparing the detection of irregular pulse rate on Apple Watch and simultaneous electrocardiography (ECG) patch recordings, pulse detection algorithm had an 84% positive predictive value.

During ECG patch monitoring, participants’ smartwatches continued to track pulse irregularities. If an irregular pulse was detected, 84% of the time this was confirmed to be atrial fibrillation on the simultaneous ECG patch.

Researchers believe the information from this study could be used towards further clinical analysis.

Turakhia added that a survey of participants notified about irregular-pulse showed that 76% contacted either the telehealth provider or a non-study provider, indicating several participants sought medical attention.